At the time of the accident you were over the prescribed drink driving limit and as such you were arrested (although you omit that reading ) however then on the evidential machine you blew 38 , probably the lower of 2 readings on that machine. In all probability the decision not to prosecute is that the reading is so close to the limit the DPP do not deem it worthwhile to continue to court. This does not negate that an offence has been committed.
You say you had one drink with your family having a meal, a totally distancing measure from you hoping to justify drink driving, also you further distance yourself by claiming the third party pulled out on you while you was doing 20mph and still the whole side of your car is in your opinion written off (@ 20 mph?) think yourself very lucky it wasnt a cyclist or pedestrian that walked out or pulled out. You have notified your insurance blaming the third party conveniently omitting your arrest at the scene for drink driving. to which you freely admit to.
Your insurance will pay the third party and damage to the mobility car, however it is a real possibility that in view of your arrest they will pursue you for any and all monies incurred by them, so beware when you collect your hire car as in all probability you will be paying for it.
In short grow up accept you did wrong and now do the right thing and stop blaming every thing and every one
for your choice to drink alchohol and then get in a car and drive